CK3 By God Alone Dev Diary 4: The Christian Church Situation Explained

In Crusader Kings III, the Pope can excommunicate a rival or fund a war, yet the Church itself often stays a motionless backdrop. Dev Diary #4 for By God Alone, published on 23 June 2026, gives Paradox’s answer: one Situation shared by all of Christendom, running through seven chapters, whose calendar every Christian ruler pushes forward.

Update of 26 October 2026: By God Alone released on 30 September with patch 1.20.0 “Crozier”, at 19.99 EUR on Steam (Windows, macOS, Linux). The release changelog confirms the essentials: every Christian ruler of County tier or above takes part, six groups share the Situation and seven chapters drive it. It adds catalysts (antipopes, cardinal appointments, a Pope of the same dynasty three times in a row) and a Church window with a Great Schism gauge. The 1,000-point threshold is not repeated there, and the Great Schism becomes a separate gauge: a Crisis chapter only triggers it if that gauge has reached its threshold.

Six groups, three axes

The Situation covers Christendom, meaning every independent Christian realm whose lands fall within an archdiocese. Six participant groups split it along three axes: clerical or secular, Main Power or Secondary Powers, ecumenical or heretic.

The Main Power is the Christian faith holding the most counties in the world. It is recalculated whenever a county changes faith. If Orthodox counties overtake Catholic ones, Orthodoxy becomes the Main Power, and that shift can itself act as a catalyst and push the Church into the Reform Phase.

Seven chapters, four types

Each chapter is named after an era of Church history and belongs to one of four types. Instability makes rite changes and excommunications easier. Crisis makes indulgences cheaper and councils more frequent. Zeal favours conversions and holy wars. Stability speeds up Grand Cathedrals.

• Fragile Unity (instability) opens the 867 game.
• Saeculum Obscurum (crisis) lets secular rulers appoint their court chaplains, and clergy may marry.
• Conversion Phase (zeal) makes the Main Power faith convert counties 50% faster.
• Reform Phase (instability) makes excommunications cheaper.
• Investiture Controversy (crisis) pits the crown against the Church over appointments.
• Crusade Phase (zeal) clears the great holy war cooldown of every Christian faith.
• Concord (stability) lets rulers try to mend the Great Schism.

According to Dev Diary #4, the Great Schism is created automatically at the end of Saeculum Obscurum unless players have already settled it through decisions. The final version softened this rule (see the update).

Catalysts push the next chapter

From any given chapter, only a handful of future chapters can be reached. Each accumulates points through catalysts and takes over at 1,000 points. Any eligible Christian ruler can trigger them, with no limit on repeats.

The Dev Diary groups its examples by theme. Clerical scandal: simony, embezzlement, clergy marrying or having children, a murdered head of faith. Secular interference: imprisoning a head of faith, replacing realm priests. Religious change: county conversions to or from Christianity, heresy outbreaks. War and holy sites: Jerusalem lost or reclaimed. Devotion: ecumenical councils hosted, great project contributions.

Two events shortcut the calendar. If the Catholic head of faith does not control the de jure capital of the Papal States during Fragile Unity, Saeculum Obscurum starts at once. If the Main Power faith changes during Saeculum Obscurum, the Church jumps straight to the Reform Phase.

Steering the Church yourself

The Guide the Christian Church decision is open to pious, learned or powerful rulers once every ten years, at a high piety cost. You pick the target chapter and fire a massive 75-point catalyst. The release changelog adds that the Head of Faith gets four times the effect.

The Dev Diary also describes the Pope’s bulls, such as calling a crusade or condemning a heresy. They are covered in our playable Pope preview.

What matters for a campaign

What matters is that the Church’s calendar belongs to everyone. A rival launching a crusade can force a phase on you that does not suit you, and losing Rome can change the Situation. The weight of each catalyst remains to be checked in game, since the Dev Diary gives no figures.

What to watch since release: Dev Diary #7 of 22 September says chapters can follow each other fairly freely regardless of order, and that the Great Schism runs on a second track. The Investiture Controversy is detailed in our article on Dev Diary #5.

For the basics of the game, our beginner’s guide to Crusader Kings 3 remains the starting point.

Going further

• The Investiture Controversy, Dev Diary #5
• The playable Pope in By God Alone
• The Crusader Kings 3 hub